In an interview with RFE/RL on November 7, Rasmussen said Russians felt "humiliated and betrayed during the 1990s and that is the reason why there is a strong Russian desire to restore Russian greatness in the former Soviet Union territory."

Rasmussen said he is "concerned that this may last as long as the Cold War."

Relations between NATO and Moscow have deteriorated since Russia seized and illegally annexed the Crimean Peninsula in 2014.

NATO suspended all military and political cooperation with the Kremlin, even though political and military channels of communication remain open.

In response to Russia's activities in Ukraine, NATO agreed earlier in 2016 to create four battle groups in the Baltic states and Poland with a total of 4,000 troops that should be ready in early 2017.